Annuloplasty prostheses for heart valves are well known as is shown, for example, by Alfieri et al. U.S. patent application publication US 2002/0173844 A1 and Bolling et al. U.S. patent application publication US 2003/0093148 A1. Such prostheses may be complete rings (e.g., as in the above-mentioned Alfieri et al. and Bolling et al. references), or they may be less than complete rings (e.g., as in Carpentier U.S. Pat. No. 3,656,185). The term “annuloplasty” is used herein to refer to both of these types of prostheses (i.e., both complete rings and less than completely annular structures (e.g., generally C-shaped structures)).
Typical annuloplasty prostheses include a core member surrounded by a soft fabric cover. The core member is often substantially rigid or at least semi-rigid and not penetrable by a suture needle and suture material. The fabric cover may be designed to cushion the prosthesis, and possibly also to promote tissue in-growth into the prosthesis to help integrate the prosthesis into the patient's body. It is often desired to secure the prosthesis in the patient by passing one or more suture needles and suture material through the fabric cover and adjacent tissue. Tightness and/or thinness of the fabric cover may make this difficult to do. Even if the surgeon is successful in getting proper engagement, the amount of fabric caught may be less than would be desirable for good tissue healing and over-growth.